Gee I miss the old Foundry Cove days when we set out survey stakes
every 10' in a grid, put a mag head on the end of a 2" x 4"  attached
to one Psion handheld to collect the mag data another Psion hooked to
the other magnetometer to chronicle the diurnal variations in sun
flare events and gather it all up on a 720K disk "notebook" computer
(if it fit spanned if it didn't)  and try to process it on a 386 Intel
with a 387 "maths" (for you Britishers) chip inside AutoCad and/or
Surfer changing pens for each of the colors on the single pen plotter.
Those were the days!

Then put the whole thing on a six wheeler drive it around the swamp
with the reflecting mirror you used with the infrared tachymeter
(rapid survey instrument) to set out the stakes every 10' to sight in
the mirror on the 6 wheeled ATV which was triggered to dump the mag
data to Psion handheld. (I think we skipped the sun flares though I
think you can get major events on the Internet easier now).

Site of the development of the world's first rifled cannon, designed
and patented by R. P. Parrott, Corbis online has some very interesting
pictures of some large ones (300 pound shells they were then called
and 4.5 inches and others later) that blew up, either the breech or
the barrel. Used extensively in the US Civil War.

(Apologies to Anthony Tripp of Texas A&M, paleo-sedimentologist, whose
worked (dove) in Antarctica since, Stony Brook U, my alma mater's
astronomy department part of the original "ozone hole" research
expedition there too)

George Myers